The objectives of this proposal are to study DNA polymerase(s) in leukemic lymphocytes, normal lymphocytes and embryonic cells. The studies include isolation and characterization of DNA polymerase(s) from unstimulated, PHA- and antigen-stimulated normal and leukemic lymphocytes. Comparisons will be made between DNA polymerase found in differentiating and proliferating embryonic cells and those found in acute and chronic lymphocytic leukemia, the rationale being that changes in proliferative function and DNA polymerase activities in leukemia may reflect growth regulating processes determined by the level of differentiation of the cells rather than their malignant state.